The present invention relates to an inductor for small-thickness windings, etc. used for, for example, transformers and the like.
A related art inductor is assembled generally by winding a cable wire a predetermined number of times around a bobbin, and thereafter mounting the bobbin on a magnetic core, for example, an EI core, a UI core, and a pot type core, etc.
There is also an inductor formed by laminating in a multi-layered state plural sheets on which coil patterns of conductors are formed, and electrically connecting the sheets together at end portions thereof to obtain a required number of windings as shown in Japanese Patent Publication (Unexamined) No. 4-274305/1992.
However, in this structure, the attaching and detaching of a bobbin to and from a winding machine, the winding of a cable wire around the bobbin and the mounting of the bobbin on a core require substantial labor, so that the structure has a problem concerning the productivity. In view of this, a mechanized structure suitable for mass production was proposed as shown in Japanese Patent Publication (Unexamined) No. 8-236361/1996).
A transformer-forming structure using a coil member obtained by forming a spiral conductor on a surface of a flexible insulating substrate is also known. For example, a structure disclosed in Japanese Patent Publication (Unexamined) No. 63-20805/1988 is obtained by forming spiral conductors, which constitute first and second windings, on both surfaces of a flexible insulating substrate, bending and laminating the resultant insulating substrate, and inserting an insulator while folding the same between opposed surfaces of the insulating substrate to form a coil member.
In the case of the structure disclosed in Japanese Patent Publication (Unexamined) No. 63-20805/1988, the laminating of the first and second windings in the axial direction of a magnetic core (which will hereinafter be referred to simply as core) is employed. This poses the following large problems. A flux leakage between the first and second windings and an eddy current loss occurring in the windings and surrounding structures increase, and an ill influence is exerted in many cases on a peripheral circuit.
An attempt was made to reduce leakage inductance of small-thickness windings, as shown in Japanese Patent Publication (Unexamined) No. 5-243057/1993) for solving the problems as described above.
According to the structure described above, spiral conductors constituting first and second windings are formed on a flexible insulating substrate, and this insulating substrate is bent and laminated so as to hold one winding between parts of the other. Namely, plural core inserting holes are arranged in the insulating substrate in the longitudinal direction thereof, and first and second spiral conductors constituting the first and second windings are formed on the portions of at least one surface of the insulating substrate which are around the core inserting holes. These first and second spiral conductors are connected together in series, and the insulating substrate is bent in blocks of spiral conductor, one winding being laminated on the other so as to be held between parts of the second-mentioned winding, whereby a coil member is formed.
However, since this structure is a laminated structure, there is not a degree of freedom of selecting the number of turns. Therefore, the use and performance of the structure is determined or fixed in advance, and the structure cannot be applied immediately to various other uses or applications.
Forming a winding by retaining a core by using metal clips is also known. In this method, the winding under the core is formed of a pattern on a circuit board, so that the soldering of an inner surface of the core is very difficult. Moreover, since a pattern is provided on the printed board, large limitations are placed on a design of the printed board.
In a large-sized power inductance handling a large current, a thick winding has to be put around a small core, and it is therefore difficult to manually manufacture inductors having uniform characteristics.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a new inductor capable of eliminating the abovementioned drawbacks encountered in the related art inductor, reducing the manday (that is, manufacturing steps) of windings, and being applied to the surface mounting techniques.
Another object of the present invention is to provide an inductor formed at a low cost and a simple construction by simplifying a winding-forming step in the production of, especially, a small-sized high power inductor.
A further object of the present invention is to provide an inductor capable of forming a winding structure by connecting conductors together in cooperation with simple slits and claws; and being manufactured easily.
According to the present invention there is provided an inductor obtained by forming conductors of a desired shape on bendable plate type support members, providing a slit in one end of each of the conductors and a claw on the other end of each of the conductors, bending the plate type support members, engaging the slits and claws with each other to form windings and provide openings in the support members, and inserting magnetic cores through the openings.
In another aspect of the present invention, there is provided an inductor obtained by forming conductors on rectangular parallelopipedal support members having openings, through which magnetic cores are inserted, between opposite surfaces of the support members with respect to one of three axial directions thereof, and engaging end portions of the conductors with each other in a plane perpendicular to the direction in which the conductors are formed, to connect the conductors to each other and thereby form windings.
Owing to this structure, it becomes possible to cover the magnetic cores with the windings provided on the support members so that the horizontal positioning of the windings and magnetic cores can be done.
In another structure of the present invention, the engaging of the conductors is done by locking together slits provided in the support members and claws provided on one end of the conductors, whereby winding structures can be formed.
It is possible to form groove-carrying bands on the support members, and operate the same bands as guides for positioning the windings and magnetic cores in the horizontal direction.
It is also possible to arbitrarily regulate the number of turns by soldering together claws provided on the support members and a mounting substrate.
In this structure, it is possible to carry out the engaging of the conductors on the outer surfaces of the magnetic cores.
It is also possible to use parts of the support members also as gap regulating sheets.
It is also possible to simultaneously carry out the positioning of the magnetic cores and a gap regulating operation by pasting gap-regulating sheets on the support members in advance.
The present invention further provides an inductor obtained by providing openings in flexible support members, forming conductors (patterns) along the openings, folding the support members along the openings to form windings, and putting together the openings of the folded support members to enable magnetic cores to be inserted therethrough.
In this structure, it is possible to arbitrarily increase the number of turns by folding the support members at the portions thereof, which are located between adjacent openings.
In this structure, it is possible to reduce a height of upper surfaces of turns by folding the support members at the portions thereof, which are located between adjacent openings along edges thereof.
In this structure, it is possible to carry out the positioning of the windings and magnetic cores by providing cut and raised openings in both side portions of the support members.
In this structure, it is possible to carry out the horizontal positioning of the windings and magnetic cores by providing a pair of opposed groove-carrying bands on the support members and engaging these bands with each other.
According to an aspect of the present invention, the inductor is obtained by forming conductors of a desired shape on bendable plate type support members, providing a slit in one end of each of the conductors, and a claw on the other end of each of the conductors, folding the plate type support members, engaging the slits and claws with each other to form windings on and openings in the support members, and inserting magnetic cores through the openings. Therefore, a winding forming step for, especially, a small-sized high power inductor can be simplified greatly. This enables the cost to be reduced, and the inductor to be applied very easily to surface mounting techniques.
According to another aspect of the present invention, the inductor is characterized by forming conductors on rectangular parallelopipedal support members provided with openings, through which magnetic cores are inserted, between opposite surfaces of the support members with respect to one of three axial directions thereof, and engaging end portions of the conductors with each other in a plane perpendicular to the direction in which the conductors are formed, to connect the conductors together and thereby form windings. Therefore, a winding forming step for, especially, a small-sized high power inductor can be simplified in the same manner as mentioned in the above case. This enables the cost to be reduced, and the inductor to be applied very easily to surface mounting techniques.
Besides these inductors, a structure in which the windings provided on the support members cover the magnetic cores is capable of carrying out the horizontal positioning of the windings and magnetic cores, and attaining this positioning operation very easily.
Since winding structures are formed by engaging the conductors with each other by locking together the slits provided in the support members and the claws provided at one end of the conductors, the engagement of the conductors can be attained by a very simple structure.
The groove-carrying bands are formed on the support members and operated as guides for horizontally positioning the windings and magnetic cores, so that the positioning of these parts can be done easily.
The number of turns can be regulated arbitrarily by soldering together the claws provided on the support members and a mounting substrate.
Since the engaging of the conductors with each other is done on outer surfaces of the magnetic cores, the assembling work for the manufacturing of the conductor can be carried out easily.
Since parts of the support members are used also as gap regulating sheets, the construction of the inductor can be simplified.
In a structure in which gap-regulating sheets are pasted in advance on the support members, the magnetic core positioning operation and gap-regulating operation can be carried out simultaneously.
According to still another aspect of the present invention, the inductor is obtained by providing openings in flexible support members, forming conductors (patterns) along the openings, folding the support members along the openings to form windings, and putting together the openings of the folded support members to enable magnetic cores to be inserted therethrough. This structure enables an inductor of a simple construction having a high degree of freedom of selecting the number of turns, and an adaptability to surface mounting techniques to be formed.
In this structure in which the support members are folded at the portions between adjacent openings, the number of turns can be arbitrarily increased.
In a structure in which the support members are folded at the portions thereof that are between adjacent holes along edges thereof, a height of upper surfaces of the turns can be reduced.
Providing cut and raised openings in both side portions of the support members enables the positioning of the windings and magnetic cores to be done.
In a structure in which a pair of opposed groove-carrying bands are provided on the support members, the horizontal positioning of the windings and magnetic cores can be attained simply by engaging the groove-carrying bands with each other.